Mountain Pass is an

unincorporated community An unincorporated area is a region that is not governed by a local municipal corporation. Widespread unincorporated communities and areas are a distinguishing feature of the United States and Canada. Most other countries of the world either have ...

San Bernardino County San Bernardino County (), officially the County of San Bernardino, is a county located in the southern portion of the U.S. state of California, and is located within the Inland Empire area. As of the 2020 U.S. Census, the population was 2,181, ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, United States. It is situated on

Interstate 15 Interstate 15 (I-15) is a major Interstate Highway System, Interstate Highway in the western United States, running through Southern California and the Intermountain West. I-15 begins near the Mexico–United States border, Mexican border i ...

in the southeast mountainous desert region of the state approximately from the

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

border at an elevation of —the highest point along I-15 between California and Nevada. It has a population of 30. The most prominent feature of the town, and its reason for existence, is the

Mountain Pass Mine The Mountain Pass Mine, owned by MP Materials, is an open-pit mine of rare-earth elements on the south flank of the Clark Mountain Range in California, southwest of Las Vegas, Nevada. In 2020 the mine supplied 15.8% of the world's rare-earth ...

, an open pit mine for

rare-earth element The rare-earth elements (REE), also called the rare-earth metals or (in context) rare-earth oxides or sometimes the lanthanides (yttrium and scandium are usually included as rare earths), are a set of 17 nearly-indistinguishable lustrous silve ...

s. The mine and its associated processing facilities are owned by

MP Materials MP Materials Corp. is an American rare-earth materials company headquartered in Las Vegas, Nevada. MP Materials owns and operates the Mountain Pass mine, the only operating rare earth mine and processing facility in the United States. MP Materia ...

, which purchased the assets out of bankruptcy on July 10, 2017.

Climate

Typical of the High Desert, Mountain Pass has a

cold semi-arid climate A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-ar ...

(

Köppen climate classification The Köppen climate classification is one of the most widely used climate classification systems. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, notabl ...

''BSk''), Winters are chilly but also sunny, with daytime highs around 50 and nighttime lows just below freezing. Summers are hot and somewhat wetter, with July, the hottest month, having a normal high in the low 90s. Although dry weather usually prevails in most months, the wettest months are July and August when thunderstorms commonly form over the nearby mountain ranges, which can cause flash flooding. Snow is rare but not uncommon, usually falling 2-3 times a year. Most of the snow doesn't stick to the ground very long, usually melting by mid afternoon.

References

{{authority control Geology of California Unincorporated communities in California Unincorporated communities in San Bernardino County, California